Files
siftlode/backend
peter 6a35e83ded perf(feed): un-block the search GIN + inner-join the state views (E2 S3, PERF-12/16)
PERF-12: the search ORed `unaccent(channels.title) ILIKE '%q%'` straight into
the per-video predicate, which forced a full scan + detoast of every
search_vector and a per-candidate channel fetch. Pre-resolve the matching
channel ids (a few-hundred-row scan) and match `Video.channel_id.in_(ids)`
instead, so the planner keeps the search_vector GIN as a BitmapOr branch
(alongside ix_videos_channel_pub_desc). Empty match -> false() collapses the OR.

PERF-16: show=watched|hidden|in_progress used an outer join + coalesce(status,
'new'), so the planner couldn't start from the user's small video_states set.
Those views only return rows that HAVE a state, so inner-join video_states and
filter the raw column (status is NOT NULL on a present row, so it's identical).
'unwatched'/'all' keep the outer join. Dropped the now-dead position_expr.

New regression tests (test_feed_views): search returns both text- and channel-
name matches; the four watch-state views return the exact expected sets.

Measured on the prod-sized localdev reseed (prod planner, 0067/0068 applied):
- search /feed/count q=magyar: 663,463 -> 19,206 buffers (1,406 -> 31 ms; OLD
  seq-scan+detoast -> NEW BitmapOr GIN+channel index)
- search feed page: 2,908 -> 1,479 buffers (32.6 -> 1.4 ms)
- show=watched (user with 64 watched): 40,661 -> 264 buffers (~154x)
Gate green (336 pytest, incl. the 2 new equivalence tests).
2026-08-18 04:41:16 +02:00
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